(or more technically Dynamic range compression
)is a subtle effect primarily for electric guitar
where the highest and lowest points of the sound wave
are "limited". This boosts the volume of softer picked notes
, while capping the louder ones, giving a more even level of volume. This is frequently used in country music
, where fast clean passages can sound uneven unless artificially "squashed".
Compression reduces the height of the signal to a preset level. This level can change over time. Known as 'attack', a greater attack level will give a more aggressive sound.
Another effect of compression is that it expands the length of a held note, or its sustain
. The compressor tries to keep the output level approximately the same, even if the input level is decreasing. As a result, the sustain will seem to hold at its original level longer.
Compression has a side effect of raising the background noise of a signal. This can sometimes be circumvented with a properly-configured noise gate
patched in before the compressor.
Makes of compressor
Some famous compressor pedals are the Keeley compressor, The Barber Tone Press, Maxon CP-9 Pro+, MXR Dynacomp, and the BOSS CS-3 Compression Sustainer. Read More